The couple had hoped to keep the news secret until at least Christmas, but Kate's illness prompted them to reveal it early.

Palace sources say William informed the Queen, his father, Prince Charles, and his brotherPrince Harry – the British Army captain is currently stationed in Afghanistan – before his wife was hospitalized Monday, with friends only hearing the announcement when it went public.

Not surprisingly, the pair timed the pregnancy so as not to overshadow the Queen's Diamond Jubilee, nor to disrupt a major foreign tour.